Know how to have enough fun. The trick is that a lot of people don’t know when to take a break. Being responsible, thinking about consequences and long-term thinking are really important especially from the start and I wish I had started at your age—but more people are emotionally constipated and need to let loose and do something that would excite them more often. It’s also important to know how to have fun and find things you enjoy because it helps you understand what you don’t enjoy and be able to be more resilient from displeasurable times.